ubuntu pcap抓包程序编写

安装libpcap库

sudo apt-get install libpcap-dev

程序

#include 
#include 

int main(int argc, char *argv[])
{
   pcap_t *handle;			/* Session handle */
   char *dev;			/* The device to sniff on */
   char errbuf[PCAP_ERRBUF_SIZE];	/* Error string */
   struct bpf_program fp;		/* The compiled filter */
   char filter_exp[] = "port 6000";	/* The filter expression */
   bpf_u_int32 mask;		/* Our netmask */
   bpf_u_int32 net;		/* Our IP */
   struct pcap_pkthdr header;	/* The header that pcap gives us */
   const u_char *packet;		/* The actual packet */

   /* Define the device */
   dev = pcap_lookupdev(errbuf);
   if (dev == NULL) {
       fprintf(stderr, "Couldn't find default device: %s\n", errbuf);
       return(2);
   }

   /* Find the properties for the device */
   if (pcap_lookupnet(dev, &net, &mask, errbuf) == -1) {
       fprintf(stderr, "Couldn't get netmask for device %s: %s\n", dev, errbuf);
       net = 0;
       mask = 0;
   }

   /* Open the session in promiscuous mode */
   handle = pcap_open_live(dev, 8192, 1, 1000, errbuf);
   if (handle == NULL) {
       fprintf(stderr, "Couldn't open device %s: %s\n", dev, errbuf);
       return(2);
   }
   /* Compile and apply the filter */
   if (pcap_compile(handle, &fp, filter_exp, 0, net) == -1) {
       fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp,     
       pcap_geterr(handle));
       return(2);
   }
   if (pcap_setfilter(handle, &fp) == -1) {
       fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, 
       pcap_geterr(handle));
       return(2);
   }

   /* Grab a packet */
   packet = pcap_next(handle, &header);
   /* Print its length */
   printf("Jacked a packet with length of [%d]\n", header.len);

   /* And close the session */
   pcap_close(handle);
   return(0);
}

编译

g++ main.cpp -lpcap